Cylinder leakage test

[Adger Smith]

Dan,
The Grump could have fit right into the aircraft industry.
He would have been spot on how it is done.
Leakage for aircraft is low % per cylinder and close on the variation cylinder to cylinder

[rebelrouser]

Yes, a NA engine with tight end gaps should test better than 10% on a warm engine a cold engine will read slightly more leak down. A large gap nitrous or blower engine will leak more cold. What I do is leak my engines on the stand when fresh right after taking them off the dyno cold, save those numbers. Then you have a baseline, when leakage starts to increase, I know it is time to save my pennies for a rebuild. I don't race class just bracket and index, but I see very little loss in ET until leakage gets about 30%